I know of three specific times when this particular error was made in Monterey
Co., including the first one of these I found 25 Sep 1979. According to
the field guides I was using, with the bright buffy-orange breast, a supercilium,
yellowish-green legs, and a reddish cap, it had to be a juv. Sharp-tailed
Sandpiper? Right? Wrong. What would have been the 4th MTY record of "Sharp-tailed
Sandpiper" was, in fact, the 4th MTY record of Ruff, a nice bright juv.
Ruff (like photo upper left; slightly out-of-focus, taken by Bob Tintle
years later of a different bird). What the guides failed to mention (or
I failed to notice) was back pattern. On juv. Ruff, each back and covert
feather is dark-centered, with broad buffy edges, forming a prominent "scaly"
pattern. Also the neck is thick and the body "pear-shaped," giving the
classic "Ruff" profile to the bird.

Now, Ruff has proved to be more than twice as regular a vagrant to Monterey
Co. as Sharp-tailed Sandpiper. Through fall 1998, there were 20 records
of Sharp-tailed Sandpiper compared to 47 records of Ruff. All Sharp-tailed
records fall between Sep-Nov, while Ruff records stretch almost around
the year: most in fall, a few wintering birds which linger well into spring,
and a few spring migrants. The only months which currently lack records
of Ruff are June & July.

In contrast, a real juv. Sharp-tailed Sandpiper (right) is much
more heavily streaked about the neck and upper breast, the back has a pair
of prominent white "braces" on the scapulars, the feather centers are variably
black or black-and-gray with whitish, buff, or reddish edges (depending
on which feather is involved), giving a prominent "zoned" look to the upperparts.
The bird's shape is also completely different, its supercilium more prominent
and purer white, and the undertail coverts are streaked. The tail is longer
and the contrast between orange lower breast and white belly is crisp,
totally unlike the buffy or even orange wash to the underparts of bright
juv. Ruffs. Note particularly how broad are the reddish edges to the tertials
on juv. Sharp-tailed, a nice separating feature from Pectoral Sandpiper,
even at a distance (as are the streaked undertail coverts, not to mention
breast pattern).